Fix ##50744 - Add rules for reformatting html before comparing

Fix #50744
The specification doesn't have the definition of a canonical form. When writing html through `.write()` we should be able to carry the information which is visible to users. 

This should level the playing field in between browsers with their different styles of building HTML during read/write operation of the clipboard API.

clipboard-apis/async-write-html-read-html.https.html

@@ -19,12 +19,23 @@
 // but when we are comparing for equality the spaces make a difference.
 function reformatHtml(html) {
   const parser = new DOMParser();
-  const htmlString =
-        parser.parseFromString(html, 'text/html').documentElement.innerHTML;
-  const reformattedString = htmlString.replace(/\>\s*\</g, '> <');
+  const parsedHtml = parser.parseFromString(html, 'text/html')
+
+  // More canonical form
+  // Remove the head - not visible to users
+  const headElement = parsedHtml.head;
+  if (headElement) { headElement.remove(); }
+  // Remove the eventual style attributes
+  const elementsWithStyleAttribute = parsedHtml.querySelectorAll('[style]');
+  elementsWithStyleAttribute.forEach((element) => { element.removeAttribute('style'); });
+  const htmlString = parsedHtml.documentElement.innerHTML;
+  // Remove multiple spaces and returns and replacing by one
+  // trim leading and tailing white spaces  
+  const reformattedString = htmlString.replace(/\>[\s\n]*\</g, '> <').trim();
   return reformattedString;
 }
 
+
 async function readWriteTest(textInput) {
   await tryGrantReadPermission();
   await tryGrantWritePermission();